The present invention relates to a semiconductor device and a manufacturing method thereof, and, for example, to a semiconductor device including an IGBT having a trench gate structure and a manufacturing method thereof.
In an IGBT (Insulated Gate Bipolar Transistor), a turn-off loss Eoff at switching and a saturation voltage Vce (sat) related to conduction loss are characteristics to be taken into consideration in design. However, there is a trade-off relationship between them. That is, when the turn-off loss Eoff is reduced, the saturation voltage Vce (sat) is deteriorated, and when the saturation voltage Vce (sat) is reduced, the turn-off loss Eoff is deteriorated.